Hi folks, I thought I would warn those of you who own Dimension 4600's regarding the power supply (PS). My 4600's decide to not start up last weekend at the same time. We had a power outage which should not have effected the PS on both machines. My newer 4700's are fine. I have a power regulator and separate UPS's on all my systems and network. Apparently, Dell had a problem with these PS's from the factory. They stop working soon after the warranty on the system expires. They switched to a different supplier once they found out about this problem. This effects some 4700's as well. The solution is to get a new ATX power supply from a 3rd party vendor. The PS that comes in these machines is only 250W; which isn't much for the load on it. I replaced them with 450W PS's from Microcenter made by Soly Tech. They are much quieter, a lot more powerful and a flash to replace. Make sure the PS you get is an ATX-type with a 20+4 pin on it. Hopefully some of you will find this useful. Don't bother calling Dell about the problem; the replacement power supply they provide is much weaker and much more expensive. The supplies I got were $31 each on sale now. Good luck.